Undesirable presence of one liquid in another is common. The background here focusses on those liquids which are immiscible with respect to each other. Further, only those liquids are in purview which have densities or different specific gravities with respect to each other. A commonly occurring situation fitting such boundary conditions is water which could be present in different kinds of fluids like diesel, gasoline, lubricants, et cetera. Dirt and other contaminations also ingress in fuels during transportation, mixing or storage process. Undesirable liquids, like water, can cause severe performance problems with the equipment. Conducting fluids can cause the fuel injector tips to explode, resulting in expensive repairs. Slugs of water in the fuel can cause sudden cooling in the engine and may result in shortened engine life. Excessive water can reduce the lubricating qualities of the fuel and cause injector seizure and contingent engine damage. In addition, fungus and bacteria live in water. As a result, diesel fuel needs to be filtered essentially before injecting the diesel fuel into the engine. The problems that can be caused due to contaminants and water can be a significant matter of concern. When water encumbered diesel fuel is run through a fuel system and engine, the presence of free water could result the fuel system to malfunction enormously due to rust, corrosion, deposits, etc. all of which affect the life of the machine. Undesired liquids therefore need to be detected, separated and removed.
Removal of such undesired fluid can be carried out manually by opening the appropriate outlet port. However, manual removal is only possible when there is no likelihood of useful fluid draining out inadvertently. Further, it causes inconvenience like switching off the device, and waiting for the undesired fluid to exit.
U.S. Pat. No. 6,783,665 B1 discloses a unit for automatically bleeding out water avoiding lengthy time and uncomfortable manual operations by using a sensor positioned in the collection chamber to undergo activation when the water level reaches a pre-determined maximum value. The invention uses a float assisted electrical sensor, like magnetic reed switch, and other known components. The disclosure does not elaborate construction of detecting arrangement which would ensure reliable mechanical-electrical co-ordination, and around which the unit functions. JP1984041654A, likewise, discloses an improved fuel water separator allowing efficient separation of water and associated bacterial contaminants from fuel and to keep off the outflow of fuel oil. It is done by opening a drain solenoid valve when separated water from a water sump in a fuel filter is collected more than a fixed water level, and discharging the separated water out automatically, while closing the said valve without fail when it comes into a specified low level.
Detecting presence of a liquid by its conductivity is a matter of fundamental Physics and a known art. Patent publication no US20100276352 discloses a fuel filter having water level sensor with 2 electric conductors which can be electrically interconnected by means of water if there is correspondingly high water and working on the principle of electrical resistivity. Such conductors or pins used for detecting water in fuel are commonly known as “water in fuel” pins or WIF pins. Up to three pins are commonly deployed. Patent publication no US20060070956A1, US20130285678 and US20110259802 disclose 3 pins use, achieving the objectives by providing a method for separating water from a liquid having a lighter density, by sensing the water level in the water collecting area with a water sensor and transmitting a signal indicating the sensed water level to a microprocessor. When the sensed water level in the water collecting area reaches or exceeds a predetermined maximum, the microprocessor activating the water discharge device to discharge water from water collecting area through the water outlet. An electrical resistance of the Water-in-fuel sensor changes based upon whether the qualified filter element is installed in the housing.
Many a time, the undesired liquid and or the main fluid has dirt and other micro-contamination which impair the functioning of the detection and removal over a long duration. When the undesired fluid, say water, is being bled out, a low pressure gets progressively created in the fluid vessel, which mars the steady exiting of the undesired fluid. Most designs have no redundancy. Such basic requirements are not catered to by earlier designs and which this invention effectively meets.